1. Field of the Invention
The present invention is related, in general, to a cellular phone, in particular to advertisement using cellular phones.
2. Description of the Related Art
Recent improvement in display devices installed in portable electronic apparatuses allows them to be of wide use.
Japanese unexamined patent application No. Jp-A Heisei 8-36440 discloses a portable computer including two liquid crystal display devices for facilitating an electronic presentation. The dual display device system allows information for operators to be displayed on one display device while information for clients is separately displayed on the other display device.
Japanese unexamined patent application No. Jp-A Heisei 7-72953 discloses a portable terminal including two liquid crystal display devices on the front and rear sides. Both of the liquid crystal display devices displays information inputted through input keys to allow persons other than the operator of the terminal to confirm the inputted information. At a restaurant, for example, each time a clerk inputs an order, the content of the order and a total sum are displayed on both of display devices to allow customers to confirm their orders.
Japanese unexamined patent application No. Jp-A 2001-285515 discloses a cellular phone terminal provided with a first display panel on the front side, and a second display panel on the rear side. Image data in the normal use mode (the telephone number of the other party or the like) is displayed on the first display panel, and a received still image is displayed on the second display panel. The still image may include an advertisement, a weather forecast, and an image taken in from a digital camera.
Japanese unexamined patent application No. Jp-A Heisei 8-181744 discloses that a cellular phone includes a display device detachably connected to a main unit of the cellular phone to improve usability.
Advertisement through cellular phones, which has increasingly large and clear display devices, has been considered to be one of the most advantageous advertising media. Japanese unexamined patent applications No. Jp-A 2000-315215, Jp-A Heisei 11-338870, Jp-A Heisei 11-285053, and Jp-A 2000-268090 disclose advertisement systems using cellular phones. The documents disclose that networks and servers are used to deliver advertising information. Japanese unexamined patent application No. Jp-A 2000-315215 additionally discloses that the delivered advertising information is selected on the basis of the time when the cellular phones are used. Japanese unexamined patent application No. Jp-A Heisei 11-338870 discloses that the delivered advertising information is selected on positions of the cellular phones.